Auxiliary power units (APUs) are currently used on board aircraft to provide power to support pressurized hydraulic systems, environmental control systems, and electrical systems. APU support is generally provided while the aircraft is on the ground during loading and unloading of passengers. During flight, APUs are shut down or operated only during an emergency. APUs can be problematic in that they are a significant source of weight and cost to the aircraft, while only providing short term services while on the ground.
Thus, a need exists for a more efficient system of auxiliary power. The present invention is directed to fulfilling this need by describing an auxiliary power design that provides additional thrust for takeoff and climb in addition to providing power for running conventional auxiliary equipment.